In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to adequately perform as cushioning products, they are not without disadvantages. Perhaps the most serious drawback of plastic bubble wrap and/or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet's already critical waste disposal problems. The non-biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility.
The foregoing and other disadvantages of conventional plastic packaging materials have made paper protective packaging material a very popular alternative. Paper is biodegradable, recyclable and renewable, making it an environmentally responsible choice for conscientious industries.
While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the sheets of paper into a relatively low density pad-like cushioning dunnage product. This conversion may be accomplished by a cushioning conversion machine/method, such as those disclosed in U.S. Pat. Nos. 3,509,798, 3,603,216, 3,655,500, 3,779,039, 4,026,198, 4,109,040, 4,717,613, 4,750,896, 5,134,013, 5,173,352, 5,188,581, 5,211,620, and 5,322,477 and also in pending U.S. patent application Ser. Nos. 07/840,306 abondoned and Ser. No. 07/861,225 abandoned.
With most, if not all, of the conversion machines/methods disclosed in the above-identified patents and applications, the cushioning product is created by converting multi-layer, and preferably three-layer, paper stock material into a desired geometry. The cushioning product includes pillow-like portions formed by the lateral edges of all of the layers of stock paper being rolled inwardly to form a pair of twin spirals. The central regions of this structure are then compressed and connected (such as by coining) to form a central compressed portion and two lateral pillow-like portions which essentially account for the cushioning qualitites of the product.
The central compressed portion of such a cushioning product is believed to be necessary to ensure that the pillow-like portions optimally maintain their cushioning qualities. In other words, without a connection of this type, the resiliency of the pillow-like portions would encourage the twin spirals to "unwind." However, the central portion, due to its compressed state, increases the density of the overall cushioning product.
In the past, attempts have been made to decrease the density of the cushioning products by altering its construction. Specifically, U.S. Pat. No. 4,717,613 introduced a conversion process/machine which creates a lower density cushioning product. The decrease in density is accomplished by urging the stock material outwardly into the pillow-like portions whereby the central compressed section is comprised of a lesser amount of stock material.
Despite past improvements, a need remains for paper cushioning products of even lower densities. Moreover, irrespective of particular density properties, environmental and other concerns provide a constant desire for new and effective paper cushioning products.